atmosphere, or spread on or under the ground. Of course, the more developed countries are better able to plan and otherwise cope with residuals, but they are not always able to muster the investments and social discipline to do so. Less developed countries also have environmental quality problems to a severe degree, but these appear to be somewhat more localized and for the most part have not yet assumed the megasize that one finds in the metropolitan parts of the developed countries.
Of course, the quantitative and qualitative aspects do not occur in separate compartments; they are interrelated in their occurrence, their causes, their consequences, and the ways in which they can be dealt with. For example, upgrading the quality of water in the bays and estuaries of the world, on the shores of which most of the large cities are located, will require upstream storage of larger quantities of fresh water so that the estuarial pollution can be diluted and flushed out into the ocean. The yield of crops from agricultural land is greatly enhanced by the application of fertilizers and the use of pesticides, both of which can have deleterious effects on streams and lakes and even on wildlife and human beings. A solution to the increasing scarcity of certain minerals is to be found by making larger use of lower grade ores, by going to lower quality sources. As one scans the resource field one notices an all-pervading fact: there is a set of trade-offs between the quantity and quality of natural resource commodities. Resource development policies and systems of management must recognize these interconnections. Both the objectives of development and conservation and the means for their achievement will have to include qualitative as well as quantitative aspects if they are to be wise and efficient.
In this paper we shall deal first with the more strictly quantitative side and then turn to the qualitative aspects. Finally, in our comments that bear directly on policies and management we shall be concerned with both the quantitative and the qualitative; neither the statement of the issues nor the presentation of lines of solution can be divorced from either aspect. In considering the quantitative and then the qualitative environmental questions we shall strain a bit to present statistical indicators of trends and conditions. Our indicators will not be as clear-cut and definitive as we would like; however, we do believe that better policy and management will have to be based on more than hearsay and subjective judgment. If our statistical indicators are less than satisfactory, they can at least point the way for future efforts to create a better basis for understanding and then dealing with the problems.
THE QUANTITATIVE TRENDS AND OUTLOOK FOR RESOURCE COMMODITIES
In a recent article we attempted to examine world trends in resources in terms of several indicators of scarcity (1). For each major world region, and